title: The total cavopulmonary connection resistance: a significant impact on single ventricle hemodynamics at rest and exercise.
abstract: Little is known about the impact of the total cavopulmonary connection (TCPC) on resting and exercise hemodynamics in a single ventricle (SV) circulation. The aim of this study was to elucidate this mechanism using a lumped parameter model of the SV circulation. Pulmonary vascular resistance (1.96+/-0.80 WU) and systemic vascular resistances (18.4+/-7.2 WU) were obtained from catheterization data on 40 patients with a TCPC. TCPC resistances (0.39+/-0.26 WU) were established using computational fluid dynamic simulations conducted on anatomically accurate three-dimensional models reconstructed from MRI (n=16). These parameters were used in a lumped parameter model of the SV circulation to investigate the impact of TCPC resistance on SV hemodynamics under resting and exercise conditions. A biventricular model was used for comparison. For a biventricular circulation, the cardiac output (CO) dependence on TCPC resistance was negligible (sensitivity=-0.064 l.min(-1).WU(-1)) but not for the SV circulation (sensitivity=-0.88 l.min(-1).WU(-1)). The capacity to increase CO with heart rate was also severely reduced for the SV. At a simulated heart rate of 150 beats/min, the SV patient with the highest resistance (1.08 WU) had a significantly lower increase in CO (20.5%) compared with the SV patient with the lowest resistance (50%) and normal circulation (119%). This was due to the increased afterload (+35%) and decreased preload (-12%) associated with the SV circulation. In conclusion, TCPC resistance has a significant impact on resting hemodynamics and the exercise capacity of patients with a SV physiology.
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, School of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0535, USA.
authors.forename: Kartik S
authors.initials: KS
authors.lastname: Sundareswaran
authors.forename: Kerem
authors.initials: K
authors.lastname: Pekkan
authors.forename: Lakshmi P
authors.initials: LP
authors.lastname: Dasi
authors.forename: Kevin
authors.initials: K
authors.lastname: Whitehead
authors.forename: Shiva
authors.initials: S
authors.lastname: Sharma
authors.forename: Kirk R
authors.initials: KR
authors.lastname: Kanter
authors.forename: Mark A
authors.initials: MA
authors.lastname: Fogel
authors.forename: Ajit P
authors.initials: AP
authors.lastname: Yoganathan
mesh_terms: D000293:Adolescent; D006328:Cardiac Catheterization; D002302:Cardiac Output; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D019992:Databases as Topic; D017079:Exercise Tolerance; D018729:Fontan Procedure; D006330:Heart Defects, Congenital / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D018810:Magnetic Resonance Angiography; D019028:Magnetic Resonance Imaging, Cine; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011651:Pulmonary Artery / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D011652:Pulmonary Circulation; D015203:Reproducibility of Results; D016896:Treatment Outcome; D014481:United States; D014655:Vascular Resistance; D014682:Vena Cava, Inferior / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D014683:Vena Cava, Superior / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D016276:Ventricular Function